What is sea-floor spreading? explain
Sea-floor spreading, also referred to as ocean floor spreading, is a geological process occurring at the mid-oceanic ridges where new oceanic crust is formed. It is a key component of plate tectonics theory.
Sea-floor spreading begins with the upwelling of magma from Earth's mantle at divergent plate boundaries, also known as mid-oceanic ridges. As the magma rises, it fills the gap between the separating tectonic plates. The magma then cools and solidifies, forming a new section of oceanic crust. This process is called crystallization.
As new crust is formed, the older crust is pushed away from the ridge and moves laterally. This lateral movement is driven by the continuous upwelling of new magma. The movement of the plates can be compared to a conveyor belt, where new crust is continuously added and old crust is pushed aside.
As the oceanic crust spreads away from the mid-oceanic ridge, it becomes older and denser. The rocks on either side of the ridge record the symmetrical pattern of reversal in Earth's magnetic field. These magnetic anomalies can be measured using magnetometers attached to research vessels. By analyzing the pattern and age of the rocks, scientists can calculate the rate at which the sea floor is spreading.
Sea-floor spreading plays a fundamental role in the theory of plate tectonics, as it provides an explanation for the formation and movement of the Earth's tectonic plates. It also contributes to the creation of new crust, which helps balance the loss of crust in subduction zones, where one tectonic plate sinks beneath another.